Stereoscopic projection apparatus.



M. F. SULLIVAN.

STEREOSCOP'IC PROJECTION APPARATUS.

APPLICATION FI LED AUG.24. 1914.

1,1 89,308. Patented July 4., 1915.

In U812 t witneadea:

Wm m ww ffi w' g m I Attgs.

UNITED STATES PATENT OFFICE.

indium. more sunmvm, or cmceeo, rumors.

B'IEBEOSCOPIC PROJECTION APIARATUS To all whom it may concern:

Be it known that I, MICHAEL FRANCIS SULLIVAN, a citizen of the UnitedStates of America, and a resident of Chicago, county of Cook, and Stateof Illinois, have invented certain new and useful Improvements inStereoscopic Projection Apparatus, of which the followingiisaspecification. 1

The main objects of this invention are to provide an improved apparatus'for alternately cutting off the vision from the llilllt y and left eyesof an observer so that suits. projected motion pictures, or twostationary stereoscopic views projected alternately, will be seen instereoscopic projectionby the observer; to provide in such apparatus animproved form of shutter where y each of the observers eyes will becompletely screened before the other eye receives light from thepicture; to provide improved means for operating the shutter whereby itis moved quickly and in exact sy'nchronism with the shutter of thepicture projectin machine; and to provide improved means or controllingthe operating mechanism of the shutter.

An illustrativeembodiment of this invention is shown in the accompanyingdrawings, in which: c

Figure 1 is a view showing in elevation, the observers apparatus; indiagram, the electric circuits 'for operating the same; and inperspective, the controlling means for the electric'circuit. Fig. 2 is abottom plan of the observing device with the handle re moved.

Heretoforein'devices of this class the shutters used to open and closethe apertures 'in the screen of the observing devices were of a designwhereby one of the apertures was being opened as the. other was being clsed, and when'the shutter was in a centra or neutral, position bothapertures would be partly open. With such an arrangement each of theeyes of the observer would see part of the picture intended only for theother eye, thereby destroying a part of the stereoscopic effect, andalso producing a fluttering or blurring of the plcture.

In the construction shown in the drawings, the observing device 1 isprovided with a suitable handle 2 and a body shown in the form of ascreen 3 having apertures 4 therein serving as sight openings, andspaced apart toregister with the eyes of the user. A shutter 5 havingarms 6 and 7 with depending ends 8 and 9 respectively is mounted ISpecification of Letters Patent.

with a depending arm 11 with-an armature 12 at its end. o

Operating mechanism for the shutter is provided in the form of apair ofelectromagnets 13 having U-shaped cores 14.

Means for holding the shutter in a central or neutral position when notin operation,

- and to quickly restore it to this "positlon after being. displacedtoward either side',are provided and comprise a spring arm 23 rigidlymounted on the shutter 5 and having sliding engagement between pins 24on the screen 3.

shutter 5 in synchrony with the pictures, as they are moved intoposition to be projected, comprise a controller 16 .for alternatelyopening and closing the electric circuits of conductors 17 which areconnected to the.

electro-magnets 13, thereby operating the shutter 5 by attracting thearmature 12.

The circuit controller 16 is arranged. to be attached to' the shaft 18of the operating handle of the projector 19, and comprises .two annularrows of contact segments elec- Patented July- 4, 1916. Application filedAugust 24, 1914. Serial No. 858,224. I 1

.70 The controlling means for operating the its circuit is open, but thecontact segments 1 in each row are of a slightly greater peripherallength than the insulated portions, thus insuring that each circuit willbe closed slightly in advance of theopening of the other.

In the operation of the device, a cinematograph. film 22 may be usedwhereon' the successive pictures have been taken from alternately twodifferent points of view,

preferably points spaced about the pupilary distance or more apart; andthe shutter (not shown) of the projecting machine causes the picturesfromthe right-hand point of view to be displayed alternately with thoseTaken from the left-hand point of view. Two stereoscopic stationaryviews may be also used by employinga projecting machine which displaysthe views alternately upon the screen at suitable intervals. Thecontroller 16, being directly connected with the operating handle of theprojecting machine, causes the shutter of the observers apparatus tooperate so that the opening for the right eye will be uncovered whenpictures from the right-hand point of view are displayed and vice versa.The observing device 1 is held before the eyes of the observer" opened,thereby preventing any possibilityof one of the eyes of the observerseeing a portion of the vpicture intended for the other eye.

I claim 1. A device of the class. described, comprising a body having apair of sight openings spaced apart to register with the eyes of theuser, a shutter adapted to control said sight openings comprising apivoted member having parts located to alternately close said openingsthrough the pivotal movement of said member, said parts being shaped andarranged to fully close one of said sight passages before the other is,

opened, an armature carried by said member, a pair of electro-magnetscodperatlng with said armature to oscillate said shutter,

and yielding means normally holding said parts in position to close saidopenings.

2. A device of the class described, comprising a body having a pair ofsight openings therein and spaced apart to register with the eyes of theuser, a shutter pivotally mounted on said body and adapted toalternately close said openings through pivotal movement thereof, anarmature carried by said shutter, a pair of electro-magnets disposed onopposite sidesof said armature for oscillating said shutter, a leafspring having one end attached to said shutter, and a pair of pins onsaid body for embracing the other end of said spring, said spring beingarranged t0 normally hold said shutter in position to close both saidopenings.

Signed at Chicago. this 20th day of August 1914.

M. FRANCIS SULLIVAN.

Witnesses: EUGENE A. RUMMLER, M. IRENE HUTCHINGS.

